EDCA parameters

[ASF_SVI_ITE]

Good morning!

About this topic I would like to have some clarifications: in a wireless controller  the default is WMM for the AP managed. So what does it mean that? Could APs use a minimum and a maxim time wait of transmission? As explained in the link below:

http://www.cisco.com/assets/sol/sb/AP541N_GUI/AP541N_1_9_2/help_QoS_Parameters.htm

And If it valid this assumption how is the default behaviour for a Workgroup Bridge client? Does it exist also a similar setting?

Thanks in advance

Alberto

[George Stefanick]

If I understand your question you are asking how are the timers used. There are 4 WMM categories. Voice, video, data, background. If your WLAN is configured for voice and a phone wants to send a frame it will use CSMA-CA. If the medium is busy the frame is give a cw of say 20. If a data frame at this exact time wanted to send a frame it would get a longer cm say 100. In theory the timer for voice at 20 will get to the test the medium before the data client.

If you have a client attached to a WGB his traffic is sent through the WGB and would take part in the same depending on the WLAN wmm setting.

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
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‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."

[ASF_SVI_ITE]

Hi George, thanks for the answer. Let me ask another thing: if I have only a traffic source, time sensitive, can I use EDCA to best the performance? If I have understood well EDCA permits to access to the medium more quickly, is right?

And finally, apart of this. Can I best the performance reducing the packet retries number on the APs? The default value is 64 but a collegue says me that it exists a feature called LLM that could permit to reduce it to 3. Is true? And can I obtain benefits with this setting?

Regards

Alberto

[George Stefanick]

Correct. EDCA is 802.11e / WMM. It is part of HCF and allows for QoS classes, 8 to be exact. The classes have different priority levels which translate to different back off timer lengths.

Most device will quite well before the 64 tries is my understanding ..

__________________________________________________________________________________________
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
__________________________________________________________________________________________
‎"I'm in a serious relationship with my Wi-Fi. You could say we have a connection."